The PML-RARα transcript will be monitored throughout and standard risk patients with detectable minimal residual disease by real time quantitative reverse transcriptase polymerase chain reaction (RQ-PCR+) at the end of the second consolidation block will receive a third consolidation block identical to high risk patients. Patients who are RQ-PCR+ for PML-RARα after completion of the third block of consolidation therapy will be candidates for refractory/relapse treatment, but will remain on study. Refractory/relapsed patients who remain RQ-PCR+ for PML-RARα will be candidates for allogeneic bone marrow transplantation (allo-BMT), whilst those who become RQ-PCR- for PML-RARα will have individualised treatment with ongoing MRD monitoring.